Are Australian honeybees behind U.S. hive collapse?

Disease-carrying honeybees imported from Australia may be responsible for a mysterious disorder that's decimated bee hives around the country, and federal regulators say they'd consider import restrictions if necessary.

By some estimates, beekeepers in the past several years have lost from a third to half their hives to what's called colony collapse disorder. Each hive, or colony, can contain as many as 100,000 bees. The bees are disappearing from the hives never to be seen again.

Honeybees pollinate about 100 crops, mostly fruits, vegetables and nuts. By some estimates, more than a third of the food that humans consume is pollinated by honeybees.

"Honeybees are important if you want a healthy and nutritious diet," said Robyn Rose, the Agriculture Department's national program manager for honeybee health. "We could live without them, but our diet would be pretty bland."

Scientists are unsure what's causing the problem, though it could involve a combination of factors. The possible culprits include mites, viruses, other diseases, pesticides, habitat loss, stress and even climate change. The latest suspect, however, is the imported honeybee from Australia.